more io stuff

driver/Makefile

@@ -1,30 +1,31 @@
 NAME = counter
+OBJS = init.o leds.o ls7366r.o trigger.o io.o
+KDIR := /lib/modules/$(shell uname -r)/build
+DTC_FLAGS := -@ -I dts -O dtb
+
 obj-m += $(NAME).o
+$(NAME)-objs := $(OBJS)
 
 all: $(NAME).ko $(NAME).dtbo
 	echo Builded Device Tree Overlay and kernel module
 
-$(NAME).ko: $(NAME).c
+$(NAME).ko:
-	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) modules
+	make -C $(KDIR) M=$(PWD) modules
 
 $(NAME).dtbo: $(NAME).dts
-	dtc -@ -I dts -O dtb -o $@ $<
+	dtc $(DTC_FLAGS) -o $@ $<
 
 clean:
-	make -C /lib/modules/$(shell uname -r)/build M=$(PWD) clean
+	make -C $(KDIR) M=$(PWD) clean
 	rm -rf $(NAME).dtbo
 	
 load:
-	sudo dtoverlay -d . $(NAME).dtbo
+	sudo dtoverlay -d . $(NAME).dtbo && echo "Overlay loaded"
-	@echo "Overlay loaded"
+	sudo insmod ./$(NAME).ko && echo "LKM loaded"
-	sudo insmod ./$(NAME).ko
-	@echo "LKM loaded"
 
 unload:
-	sudo rmmod ./$(NAME).ko
+	sudo rmmod ./$(NAME).ko && echo "LKM unloaded"
-	@echo "LKM unloaded"
+	sudo dtoverlay -R $(NAME) && echo "Overlay unloaded"
-	sudo dtoverlay -R $(NAME)
-	@echo "Overlay unloaded"
 
 list: 
 	sudo dtoverlay -l

driver/counter.c

@@ -1,112 +0,0 @@
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/mod_devicetable.h>
-#include <linux/property.h>
-#include <linux/platform_device.h>
-#include <linux/of_device.h>
-#include <linux/gpio/consumer.h>
-
-/* Meta Information */
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Wolfgang Hottgenroth");
-MODULE_DESCRIPTION("A simple LKM to parse the device tree for a specific device and its properties");
-
-/* Declate the probe and remove functions */
-static int dt_probe(struct platform_device *pdev);
-static void dt_remove(struct platform_device *pdev);
-
-static struct of_device_id my_driver_ids[] = {
-  {
-    .compatible = "hottis,counter",
-  }, { /* sentinel */ }
-};
-MODULE_DEVICE_TABLE(of, my_driver_ids);
-
-static struct platform_driver my_driver = {
-  .probe = dt_probe,
-  .remove = dt_remove,
-  .driver = {
-    .name = "my_device_driver",
-    .of_match_table = my_driver_ids,
-  },
-};
-
-/* GPIO variable */
-static struct gpio_desc *red_led = NULL;
-static struct gpio_desc *blue_led = NULL;
-
-
-/**
- * @brief This function is called on loading the driver 
- */
-static int dt_probe(struct platform_device *pdev) {
-  struct device *dev = &pdev->dev;
-
-  printk("counter - probing\n");
-
-  if(!device_property_present(dev, "red-led-gpio")) {
-    printk("counter - Error! Device property 'red-led-gpio' not found!\n");
-    return -1;
-  }
-  if(!device_property_present(dev, "blue-led-gpio")) {
-    printk("counter - Error! Device property 'blue-led-gpio' not found!\n");
-    return -1;
-  }
-
-
-  /* Init GPIO */
-  red_led = gpiod_get(dev, "red-led", GPIOD_OUT_LOW);
-  if(IS_ERR(red_led)) {
-    printk("counter - Error! Could not setup the GPIO red-led\n");
-    return -1 * IS_ERR(red_led);
-  }
-  blue_led = gpiod_get(dev, "blue-led", GPIOD_OUT_LOW);
-  if(IS_ERR(blue_led)) {
-    printk("counter - Error! Could not setup the GPIO blue-led\n");
-    return -1 * IS_ERR(blue_led);
-  }
-
-  return 0;
-}
-
-/**
- * @brief This function is called on unloading the driver 
- */
-static void dt_remove(struct platform_device *pdev) {
-  printk("counter - removing\n");
-  gpiod_put(red_led);
-  gpiod_put(blue_led);
-}
-
-/**
- * @brief This function is called, when the module is loaded into the kernel
- */
-static int __init my_init(void) {
-  printk("counter - Loading the driver...\n");
-  if(platform_driver_register(&my_driver)) {
-    printk("dt_gpio - Error! Could not load driver\n");
-    return -1;
-  }
-
-  printk("counter - red led on\n");
-  gpiod_set_value(red_led, 1);
-
-  return 0;
-}
-
-/**
- * @brief This function is called, when the module is removed from the kernel
- */
-static void __exit my_exit(void) {
-  printk("counter - Unload driver");
-
-  printk("counter - red led off\n");
-  gpiod_set_value(red_led, 0);
-
-  platform_driver_unregister(&my_driver);
-}
-
-module_init(my_init);
-module_exit(my_exit);
-
-

driver/counter.dts

@@ -3,14 +3,43 @@
 / {
   compatible = "brcm,bcm2835";
   fragment@0 {
-    target-path = "/";
+    target-path = "/soc";
     __overlay__ {
       status = "okay";
-      counter {
+      leds {
-        compatible = "hottis,counter";
+        compatible = "hottis,leds";
         red-led-gpio = <&gpio 26 0>; 
         blue-led-gpio = <&gpio 21 0>; 
       };
+      intr {
+        compatible = "hottis,intr";
+        intr-gpio = <&gpio 19 0>;
+      };
     };
   };
+
+  fragment@1 {
+    target = <&spidev0>;
+    __overlay__ {
+      status = "disabled";
+    };
+  };
+
+  fragment@2 {
+    target = <&spi0>;
+    __overlay__ {
+      status = "okay";
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      ls7366r: ls7366r@0 {
+        compatible = "hottis,ls7366r";
+        reg = <0x0>;
+        spi-max-frequency = <1000000>;
+        spi-bits-per-word = <8>;
+        status = "okay";
+      };
+    };
+  };
+
 };

driver/counter_io_calls.h

@@ -0,0 +1,26 @@
+#ifndef _COUNTER_IO_CALLS_H_
+#define _COUNTER_IO_CALLS_H_
+
+#ifndef __KERNEL__
+#include <stdint.h>
+#define u64 uint64_t
+#define u32 uint32_t
+#endif
+
+#include "leds_codes.h"
+
+struct observation {
+  u64 ts_sec;
+  u64 ts_nsec;
+  u32 value;
+};
+
+struct led_cmd {
+  enum led_color_e color;
+  enum led_state_e state;
+};
+
+#define LED_CMD _IOW('l', 'c', struct led_cmd *);
+
+
+#endif /* _COUNTER_IO_CALLS_H_ */

driver/init.c

@@ -0,0 +1,64 @@
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/spi/spi.h>
+
+#include "ls7366r.h"
+#include "trigger.h"
+#include "leds.h"
+#include "io.h"
+
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Wolfgang Hottgenroth");
+MODULE_DESCRIPTION("Driver for the MainsCnt measurement hat");
+
+
+
+/* module loading and unloading */
+static int __init my_init(void) {
+  printk("counter - Loading IO subsystem...\n");
+  if (io_init()) {
+    printk("counter - Error! Could not load IO subsystem\n");
+    return -1;
+  }
+        
+  printk("counter - Loading the leds driver...\n");
+  if(platform_driver_register(&leds_driver)) {
+    printk("counter - Error! Could not load leds driver\n");
+    return -1;
+  }
+
+  printk("counter - Loading the ls7366r driver...\n");
+  if (spi_register_driver(&ls7366r_driver)) {
+    printk("counter - Error! Could not load spi driver\n");
+    return -1;
+  }
+
+  printk("counter - Loading the interrupt driver...\n");
+  if(platform_driver_register(&interrupt_driver)) {
+    printk("counter - Error! Could not load interrupt driver\n");
+    return -1;
+  }
+
+  return 0;
+}
+
+static void __exit my_exit(void) {
+  printk("counter - Unloading the leds driver...\n");
+  platform_driver_unregister(&leds_driver);
+
+  printk("counter - Unloading the ls7366r driver...\n");
+  spi_unregister_driver(&ls7366r_driver);
+
+  printk("counter - Unloading the interrupt driver...\n");
+  platform_driver_unregister(&interrupt_driver);
+
+  printk("counter - Unloading IO subsystem...\n");
+  io_exit();
+}
+
+module_init(my_init);
+module_exit(my_exit);
+
+

driver/io.c

@@ -0,0 +1,53 @@
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/ioctl.h>
+
+#include "io.h"
+#include "counter_io_calls.h"
+
+
+static dev_t io_device_no;
+static struct class *io_device_class;
+static struct cdev io_device;
+
+#define DRIVER_NAME "cntiodev"
+#define DRIVER_CLASS "CounterClass"
+
+
+
+static int io_open(struct inode *device_file, struct file *instance) {
+  printk("counter - Info! io open was called\n");
+  return 0;
+}
+
+static int io_close(struct inode *device_file, struct file *instance) {
+  printk("counter - Info! io close was called\n");
+  return 0;
+}
+
+
+
+static struct file_operations fops = {
+  .owner = THIS_MODULE,
+  .open = io_open,
+  .release = io_close,
+};
+
+int io_init(void) {
+  printk("counter - Info! io init\n");
+
+  if (alloc_chrdev_region(&io_device_no, 0, 1, DRIVER_NAME) < 0) {
+    printk("counter - ERROR! Device No. could not be allocated\n");
+    return -1;
+  }
+  printk("counter - Info! Device No. Major: %d, Minor: %d was registered!\n", my_device_nr >> 20, my_device_nr & 0xfffff);
+
+
+
+  return 0;
+}
+
+void io_exit(void) {
+}
+

driver/io.h

@@ -0,0 +1,8 @@
+#ifndef _IO_H_
+#define _IO_H_
+
+
+int io_init(void);
+void io_exit(void);
+
+#endif /* _IO_H_ */

driver/leds.c

@@ -0,0 +1,99 @@
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/mod_devicetable.h>
+#include <linux/property.h>
+#include <linux/platform_device.h>
+#include <linux/of_device.h>
+#include <linux/gpio/consumer.h>
+
+#include "leds.h"
+
+
+/* leds stuff */
+static int dt_leds_probe(struct platform_device *pdev);
+static void dt_leds_remove(struct platform_device *pdev);
+
+static struct of_device_id leds_driver_ids[] = {
+  {
+    .compatible = "hottis,leds",
+  }, 
+  {},
+};
+MODULE_DEVICE_TABLE(of, leds_driver_ids);
+
+struct platform_driver leds_driver = {
+  .probe = dt_leds_probe,
+  .remove = dt_leds_remove,
+  .driver = {
+    .name = "leds_device_driver",
+    .of_match_table = leds_driver_ids,
+  },
+};
+
+static struct gpio_desc *red_led = NULL;
+static struct gpio_desc *blue_led = NULL;
+
+static int dt_leds_probe(struct platform_device *pdev) {
+  struct device *dev = &pdev->dev;
+
+  printk("counter - leds probing\n");
+
+  if(!device_property_present(dev, "red-led-gpio")) {
+    printk("counter - Error! Device property 'red-led-gpio' not found!\n");
+    return -1;
+  }
+  if(!device_property_present(dev, "blue-led-gpio")) {
+    printk("counter - Error! Device property 'blue-led-gpio' not found!\n");
+    return -1;
+  }
+
+
+  /* Init GPIO */
+  red_led = gpiod_get(dev, "red-led", GPIOD_OUT_LOW);
+  if(IS_ERR(red_led)) {
+    printk("counter - Error! Could not setup the GPIO red-led\n");
+    return -1 * IS_ERR(red_led);
+  }
+  blue_led = gpiod_get(dev, "blue-led", GPIOD_OUT_LOW);
+  if(IS_ERR(blue_led)) {
+    printk("counter - Error! Could not setup the GPIO blue-led\n");
+    return -1 * IS_ERR(blue_led);
+  }
+
+  printk("counter - red led on\n");
+  gpiod_set_value(red_led, 1);
+
+  return 0;
+}
+
+static void dt_leds_remove(struct platform_device *pdev) {
+  printk("counter - red led off\n");
+  gpiod_set_value(red_led, 0);
+
+  printk("counter - leds removing\n");
+  gpiod_put(red_led);
+  gpiod_put(blue_led);
+}
+
+void led_ctrl(enum led_color_e color, enum led_state_e state) {
+  struct gpio_desc *led;
+  switch (color) {
+    case e_RED:
+      led = red_led;
+      break;
+    case e_BLUE:
+      led = blue_led;
+      break;
+  }
+  int st;
+  switch (state) {
+    case e_ON:
+      st = 1;
+      break;
+    case e_OFF:
+      st = 0;
+      break;
+  }
+  gpiod_set_value(led, st);
+}
+

driver/leds.h

@@ -0,0 +1,13 @@
+#ifndef _LEDS_H_
+#define _LEDS_H_
+
+#include <linux/platform_device.h>
+
+#include "leds_codes.h"
+
+
+extern struct platform_driver leds_driver;
+
+void led_ctrl(enum led_color_e color, enum led_state_e state);
+
+#endif /* _LEDS_H_ */

driver/leds_codes.h

@@ -0,0 +1,7 @@
+#ifndef _LEDS_CODES_H_
+#define _LEDS_CODES_H_
+
+enum led_color_e { e_RED, e_BLUE };
+enum led_state_e { e_ON, e_OFF };
+
+#endif /* _LEDS_CODES_H_ */

driver/ls7366r.c

@@ -0,0 +1,142 @@
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/mod_devicetable.h>
+#include <linux/property.h>
+#include <linux/platform_device.h>
+#include <linux/of_device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/spi/spi.h>
+
+#include "ls7366r_registers.h"
+#include "ls7366r.h"
+
+
+/* spi stuff */
+static int dt_ls7366r_probe(struct spi_device *client);
+static void dt_ls7366r_remove(struct spi_device *client);
+
+/*    LS7366R functions */
+static int writeCmd(struct spi_device *client, u8 c) {
+  u8 buf[1];
+  buf[0] = c;
+  return spi_write(client, buf, 1);
+}
+
+static int writeCmdData(struct spi_device *client, u8 c, u8 d) {
+  u8 buf[2];
+  buf[0] = c;
+  buf[1] = d;
+  return spi_write(client, buf, 2);
+}
+
+static int read32(struct spi_device *client, u8 c, u32 *r) {
+  u8 tx_buf[5];
+  tx_buf[0] = c;
+  u8 rx_buf[5];
+  struct spi_transfer t = {
+    .tx_buf = tx_buf,
+    .rx_buf = rx_buf,
+    .len = 5,
+  };
+  int ret = spi_sync_transfer(client, &t, 1);
+  if (ret < 0) {
+    printk("counter - Error! spi_sync_transfer failed in read32\n");
+    return ret;
+  }
+  *r = ((u32)rx_buf[1] << 24) | ((u32)rx_buf[2] << 16) | ((u32)rx_buf[3] << 8) | ((u32)rx_buf[4]);
+  return 0;
+}
+
+int read_otr(struct spi_device *client, u32 *r) {
+  return read32(client, CMD_RD | REG_OTR, r);
+}
+
+static int read8(struct spi_device *client, u8 c, u8 *r) {
+  u8 tx_buf[2];
+  tx_buf[0] = c;
+  u8 rx_buf[2];
+  struct spi_transfer t = {
+    .tx_buf = tx_buf,
+    .rx_buf = rx_buf,
+    .len = 2,
+  };
+  int ret = spi_sync_transfer(client, &t, 1);
+  if (ret < 0) {
+    printk("counter - Error! spi_sync_transfer failed in read8\n");
+    return ret;
+  }
+  *r = rx_buf[1];
+  return 0;
+}
+
+
+static struct of_device_id ls7366r_driver_ids[] = {
+  {
+    .compatible = "hottis,ls7366r",
+  }, {}
+};
+MODULE_DEVICE_TABLE(of, ls7366r_driver_ids);
+
+static struct spi_device_id ls7366r[] = {
+  { "ls7366r", 0 },
+  {},
+};
+MODULE_DEVICE_TABLE(spi, ls7366r);
+
+struct spi_driver ls7366r_driver = {
+  .probe = dt_ls7366r_probe,
+  .remove = dt_ls7366r_remove,
+  .id_table = ls7366r,
+  .driver = {
+    .name = "ls7366r_device_driver",
+    .of_match_table = ls7366r_driver_ids,
+  },
+};
+
+struct spi_device *ls7366r_spi_client;
+
+static int dt_ls7366r_probe(struct spi_device *client) {
+  printk("counter - ls7366r probing\n");
+  
+  int ret = spi_setup(client);
+  if (ret < 0) {
+    printk("counter - Error! Failed to set up the SPI bus\n");
+    return ret;
+  }
+
+  ret = writeCmd(client, CMD_CLR | REG_STR);
+  if (ret < 0) {
+    printk("counter - Error! writeCmd 1 failed in probe\n");
+    return ret;
+  }
+  ret = writeCmd(client, CMD_CLR | REG_CNTR);
+  if (ret < 0) {
+    printk("counter - Error! writeCmd 2 failed in probe\n");
+    return ret;
+  }
+  ret = writeCmdData(client, CMD_WR | REG_MDR0, MDR0_ILO);
+  if (ret < 0) {
+    printk("counter - Error! writeCmdData failed in probe\n");
+    return ret;
+  }
+
+  u8 x;
+  ret = read8(client, CMD_RD | REG_MDR0, &x);
+  if (ret < 0) {
+    printk("counter - Error! read8 failed in probe\n");
+    return ret;
+  }
+  if (x != MDR0_ILO) {
+    printk("counter - Error! failed to initialize counter\n");
+    return -1;
+  }
+
+  ls7366r_spi_client = client;
+
+  return 0;
+}
+
+static void dt_ls7366r_remove(struct spi_device *client) {
+  printk("counter - ls7366r removing\n");
+}
+

driver/ls7366r.h

@@ -0,0 +1,11 @@
+#ifndef _LS7366R_H_
+#define _LS7366R_H_
+
+#include <linux/spi/spi.h>
+
+extern struct spi_driver ls7366r_driver;
+extern struct spi_device *ls7366r_spi_client;
+
+int read_otr(struct spi_device *client, u32 *r);
+
+#endif /* _LS7366R_H_ */

driver/ls7366r_registers.h

@@ -0,0 +1,53 @@
+#ifndef _LS7366R_REGISTERS_H_
+#define _LS7366R_REGISTERS_H_
+
+#define REG_MDR0  0b00001000
+#define REG_MDR1  0b00010000
+#define REG_DTR   0b00011000
+#define REG_CNTR  0b00100000
+#define REG_OTR   0b00101000
+#define REG_STR   0b00110000
+
+#define CMD_CLR   0b00000000
+#define CMD_RD    0b01000000
+#define CMD_WR    0b10000000
+#define CMD_LOAD  0b11000000
+
+#define STR_CY    0b10000000
+#define STR_BW    0b01000000
+#define STR_CMP   0b00100000
+#define STR_IDX   0b00010000
+#define STR_CEN   0b00001000
+#define STR_PLS   0b00000100
+#define STR_UD    0b00000010
+#define STR_S     0b00000001
+
+#define MDR0_NOQ  0b00000000
+#define MDR0_Q1   0b00000001
+#define MDR0_Q2   0b00000010
+#define MDR0_Q4   0b00000011
+#define MDR0_FRC  0b00000000
+#define MDR0_SCC  0b00000100
+#define MDR0_RLC  0b00001000
+#define MDR0_MNC  0b00001100
+#define MDR0_DI   0b00000000
+#define MDR0_ILC  0b00010000
+#define MDR0_IRC  0b00100000
+#define MDR0_ILO  0b00110000
+#define MDR0_AI   0b00000000
+#define MDR0_SI   0b01000000
+#define MDR0_FC1  0b00000000
+#define MDR0_FC2  0b10000000
+
+#define MDR1_4CM  0b00000000
+#define MDR1_3CM  0b00000001
+#define MDR1_2CM  0b00000010
+#define MDR1_1CM  0b00000011
+#define MDR1_EC   0b00000000
+#define MDR1_DC   0b00000100
+#define MDR1_F_IDX  0b00010000
+#define MDR1_F_CMP  0b00100000
+#define MDR1_F_BW   0b01000000
+#define MDR1_F_CY   0b10000000
+
+#endif /* _LS7366R_REGISTERS_H_ */

driver/trigger.c

@@ -0,0 +1,129 @@
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/mod_devicetable.h>
+#include <linux/property.h>
+#include <linux/platform_device.h>
+#include <linux/of_device.h>
+#include <linux/gpio/consumer.h>
+#include <linux/spi/spi.h>
+#include <linux/interrupt.h>
+#include <linux/of_irq.h>
+#include <linux/workqueue.h>
+#include <linux/timekeeping.h>
+
+#include "ls7366r.h"
+#include "leds.h"
+
+
+
+
+
+/* interrupt stuff */
+static int dt_interrupt_probe(struct platform_device *pdev);
+static void dt_interrupt_remove(struct platform_device *pdev);
+
+static struct of_device_id interrupt_driver_ids[] = {
+  {
+    .compatible = "hottis,intr",
+  }, 
+  {},
+};
+MODULE_DEVICE_TABLE(of, interrupt_driver_ids);
+
+struct platform_driver interrupt_driver = {
+  .probe = dt_interrupt_probe,
+  .remove = dt_interrupt_remove,
+  .driver = {
+    .name = "interrupt_device_driver",
+    .of_match_table = interrupt_driver_ids,
+  },
+};
+
+static struct gpio_desc *counter_interrupt;
+static int irq_number;
+
+// workqueue
+struct counter_irq_data {
+  struct work_struct work;
+  u64 timestamp;
+  struct spi_device *client;
+  struct timespec64 current_timestamp;
+  struct timespec64 last_timestamp;
+  u32 last_value;
+};
+static struct counter_irq_data counter_irq_wq_data;
+
+static void counter_worker(struct work_struct *work) {
+  struct counter_irq_data *data = container_of(work, struct counter_irq_data, work);
+
+  u32 counter_value;
+  int ret = read_otr(data->client, &counter_value);
+
+  if (ret < 0) {
+    printk("counter - Error! read32 failed in counter_worker\n");
+    return;
+  }
+
+  if (data->last_value) {
+    u32 period = counter_value - data->last_value;
+    printk("counter %lld.%09lu %u\n", 
+        (s64)((data->current_timestamp).tv_sec), 
+        ((data->current_timestamp).tv_nsec), 
+        period);
+
+
+  }
+  data->last_value = counter_value;
+  data->last_timestamp = data->current_timestamp;
+}
+
+// ISR
+static irqreturn_t counter_isr(int irq, void *dev_id) {
+  ktime_get_real_ts64(&counter_irq_wq_data.current_timestamp);
+  schedule_work(&counter_irq_wq_data.work);
+  return IRQ_HANDLED;
+}
+
+static int dt_interrupt_probe(struct platform_device *pdev) {
+  struct device *dev = &pdev->dev;
+
+  printk("counter - interrupt probing\n");
+
+  INIT_WORK(&counter_irq_wq_data.work, counter_worker);
+  counter_irq_wq_data.client = ls7366r_spi_client;
+  counter_irq_wq_data.last_value = 0;
+
+  counter_interrupt = gpiod_get(dev, "intr", GPIOD_IN);
+  if (IS_ERR(counter_interrupt)) {
+    printk("counter - Error! Could not setup the GPIO intr\n");
+    return -1 * IS_ERR(counter_interrupt);
+  }
+
+  irq_number = gpiod_to_irq(counter_interrupt);
+  if (irq_number < 0) {
+    printk("counter - Error! Could not map GPIO to IRQ\n");
+    gpiod_put(counter_interrupt);
+    return irq_number;
+  }
+  printk("counter - Info! IRQ %d assigned\n", irq_number);
+
+  int ret = request_irq(irq_number, counter_isr,
+      IRQF_TRIGGER_RISING, "gpio19_irq", dev);
+  if (ret) {
+    printk("counter - Error! Could not request IRQ\n");
+    gpiod_put(counter_interrupt);
+    return ret;
+  }
+
+  printk("counter - Info! Interrupt assigned\n");
+
+  return 0;
+}
+
+static void dt_interrupt_remove(struct platform_device *pdev) {
+  printk("counter - interrupt removing\n");
+  struct device *dev = &pdev->dev;
+  free_irq(irq_number, dev);
+  gpiod_put(counter_interrupt);
+}
+

driver/trigger.h

@@ -0,0 +1,8 @@
+#ifndef _TRIGGER_H_
+#define _TRIGGER_H_
+
+#include <linux/platform_device.h>
+
+extern struct platform_driver interrupt_driver;
+
+#endif /* _TRIGGER_H_ */